POS1271 LONGITUDINAL TRENDS IN MULTIMORBIDITY IN SYSTEMIC SCLEROSIS: RESULTS FROM AN INCIDENT POPULATION-BASED COHORT (1980-2018)
Authors: A. Makol, A. Karn, S. Achenbach, A. M. Hinze, C. S. Crowson
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Systemic sclerosis (SSc) is a chronic inflammatory autoimmune disease characterized by vascular dysfunction and widespread internal organ fibrosis. Multimorbidity (MM), defined as the co-occurrence of two or more chronic conditions, can impact life expectancy, increase risk of hospitalizations, healthcare resource utilization and reduce quality of life. The accrual of MM in SSc and its determinants are not well studied. <h3>Objectives</h3> To assess the longitudinal trends of MM (i.e., the presence of ≥2 morbidities) in an incident population-based cohort of patients with SSc vs. age- and sex-matched non-SSc comparators, and identify drivers of these trends. <h3>Methods</h3> A population-based cohort of incident physician diagnosed SSc patients between Jan 1, 1980, to Dec 31, 2018, was identified and compared to a 2:1 cohort of age- and sex-matched non-SSc comparators from the same population. Patients were followed until death, migration from the geographic area, or Dec 31, 2021. Data on 21 morbidities identified by the US Department of Health and Human Services (DHHS) and 13 morbidities included in the Charlson Comorbidity Index (CCI) was retrieved. Cumulative incidence of MM (MM2+) or substantial MM (MM5+; ≥ 5 morbidities) adjusting for the competing risk of death was estimated. Cox models adjusted for age, sex, index year and morbidity count at index date were used to compare cases and comparators. Patients who met criteria of event type before index date were excluded from respective analyses. <h3>Results</h3> 85 patients with SSc were compared to 170 age- and sex-matched non SSc comparators (mean age 55.4 y, 91% female, 90% white/non-Hispanic). At incidence/index date, a significantly higher prevalence of chronic obstructive pulmonary disease (COPD) (14% vs 4%, p=0.004), arthritis (33% vs 22%, p=0.054), peripheral vascular disease (40% vs 2%, p&lt; 0.001) and liver disease (5% vs 1%, p=0.04) were noted in patients with SSc. During a mean length of follow-up of 12.4 y (SD 9.8) for SSc &amp; 15.5 y (SD 9.8) for comparators, the development of DHHS morbidities of heart failure (HF) (HR 2.90; 95% confidence interval [CI] 1.46-5.74), cardiac arrhythmia (hazard ratio [HR] 1.60; 95% CI 1.03-2.49), stroke (HR 2.08; 95% CI 1.04-4.16), chronic kidney disease (HR 1.86; 95% CI 1.09-3.18), and COPD (HR 2.02; 95% CI 1.08-3.80) were higher in SSc vs. non-SSc comparators. While osteoporosis (HR 2.03; 95% CI 1.18-3.51) was also higher in SSc patients, it did not reach statistical significance when adjusted for baseline morbidity count at index date. Similarly, CCI morbidities of HF (HR 2.86; 95% CI 1.51-5.42), peripheral vascular disease (HR 11.32; 95% CI 6.59-19.44), cerebrovascular disease (HR 2.43; 95% CI 1.26-4.72), chronic pulmonary disease (HR 3.82; 95% CI 2.18-6.69), moderate/severe renal disease (HR 2.32; 95% CI 1.30-4.16), and any liver disease (HR 3.02; 95% CI 1.32-6.92) were also significantly higher in SSc when compared to non-SSc comparators. The cumulative incidence of DHHS MM2+ during follow-up did not differ, but the development of DHHS MM5+ was significantly higher in SSc patients vs. comparators at 10 (44% vs 32%), 15 (52% vs 45%) and 20 (64% vs 58%) years of follow up (HR 1.58; 95% CI 1.09-2.31). The development of CCI-MM2+ (HR 4.56; 95% CI 3.00-6.93) was significantly higher among SSc patients but CCI-MM5+ was not statistically significant after adjusting for morbidity count at index (HR 1.65; 95% CI 0.80-3.43). <h3>Conclusion</h3> Multimorbidity is significantly more prevalent in patients with SSc and adds a substantial healthcare burden on these patients. Patients with SSc have a 1.5-3 fold higher risk of developing multiple cardiopulmonary morbidities and &gt;10 fold higher risk of developing peripheral vascular disease during longitudinal follow up than age- and sex-matched individuals without SSc. Multimorbidity assessment must be prioritized early in the disease course to reduce healthcare utilization and optimize long-term outcomes in this population. <h3>Acknowledgements</h3> This work was made possible using the resources of the Rochester Epidemiology Project, which is supported by the National Institute of Aging of the NIH (R01 AG034676). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. <h3>Disclosure of Interests</h3> Ashima Makol Consultant of: Boehringer Ingelheim, Anukul Karn: None declared, Sara Achenbach: None declared, Alicia M. Hinze: None declared, Cynthia S. Crowson Grant/research support from: Pfizer.